The experimental study of tissue integration into porous titanium implants.

INTRODUCTION: Due to a lack of uniform shapes and sizes of bone defects in hip and knee joint pathology, their fixing could benefit from using individually manufactured 3D-printed highly porous titanium implants. The objective of this study was to evaluate the extent of bone and muscle tissue integration into porous titanium implants manufactured using additive technology. MATERIALS AND METHODS: Porous and non-porous titanium plates were implanted into the latissimus dorsi muscle and tibia of 9 rabbits. On days 1, 60 and 90 animals were examined with x-rays. On day 60 histological tests were carried out. On day 90 the tensile strength at the implant-tissue interface was tested. RESULTS: Histological analysis of muscle samples with porous titanium implants showed integration of connective tissue and blood vessels into the pores. Bone defect analysis demonstrated bone ingrowth into the pores of titanium with a minimal amount of fibrous tissue. The tensile strength of the muscular tissue attachment to the porous titanium was 28 (22-30) N which was higher than that of the control group 8.5 (5-11) N. Bone tissue attachment strength was 148 (140-152) N in the experimental group versus 118 (84-122) N in the control group. CONCLUSIONS: Using additive technology in manufacturing 3D-printed highly porous titanium implants improves bone and muscle integration compared with the non-porous material of the control group. This could be a promising approach to bone defect repair in revision and reconstruction surgery.

Room temperature/Corcoran/Dow Corning™-Silicone plastination process.

For 20 years, the cold temperature/S10/von Hagens' plastination technique was used to preserve biological specimens without challenge. It became the "gold standard" for preservation of beautiful, dry biological specimens. Near the end of the 21st century, a group from the University of Michigan and environs and Dow Corning™, USA, combined silicone ingredients, similar to the von Hagens' plastination products, however in a different sequence. The new polymer (Cor-tech) was combined with the cross-linker to design the "impregnation mix" which would invade the cellular structure of the specimen and yet was stable at room temperature. Later, curing would be by application of the catalyst onto the impregnated specimen. This unique sequencing of products would become the "Room temperature/Dow Corning™/Corcoran-Silicone plastination technique." The results of this room temperature technique provided similar plastinates, beautiful and practical for demonstration, containing no toxic chemical residues and forever preserved. As the name implies, impregnation of this silicone mix could be done at room temperature, without having to be kept cold. Both processes (cold and room temperature) required the same four basic steps for plastination. As well, both processes used similar basic polymers and additives to produce plastinates. However, they were combined in a different sequence. Cold temperature combines polymer and catalyst/chain extender, which is not stable and therefore must be kept colder than -15°C, while room temperature combines polymer with cross-linker which is stable, and likely forever.